1. Field of the Invention
The present invention relates to a plasma display panel (PDP) and a method of fabricating the same and more particularly, to a PDP having pairs of sustain electrodes that extend in parallel and covered with a dielectric layer and selection electrodes that extend perpendicular to the pairs of sustain electrodes, and a method of fabricating the PDP.
2. Description of the Prior Art
PDPs can be readily fabricated as large-sized flat display panels and therefore, they have been used for display devices of personal computers and workstations, wall-mounted television (TV) sets, and so on.
An example of the configuration of prior-art PDPs is shown in FIGS. 1A to 1C, which is of the surface-discharge type.
As shown in FIGS. 1A to 1C, this prior-art PDP includes first and second components 101 and 102 coupled together. The components 101 and 102 are of a plate shape.
The first component 101 has a first lass substrate 111, pairs of strip-shaped sustain electrodes 112 and 115 formed on the inner flat surface of the substrate 111, a dielectric layer 113 formed on the inner surface of the substrate 111 to cover the pairs of sustain electrodes 112 and 115, and a magnesium oxide (Mg0) layer 114 formed on the dielectric layer 113. The pairs of sustain electrodes 112 and 115, which extend in parallel to each other, are arranged at a specific pitch. Each of the sustain electrodes 112 is apart from a corresponding (or pair-forming) one of the sustain electrodes 115 by a specific distance. The dielectric layer 113 is made of low melting-point glass such as lead monoxide (Pb0)-system glass. The Mg0 layer 114 is used to protect the dielectric layer 113.
On the other hand, the second component 102 has a second glass substrate 121, strip-shaped selection electrodes 122 formed on the inner flat surface of the substrate 121, a dielectric layer 123 formed on the inner surface of the substrate 121 to cover the selection electrodes 122, partition walls 125 formed on the dielectric layer 123 to extend in parallel to the selection electrodes 122, and strip-shaped fluorescent layers 124 formed on the dielectric layer 123. The selection electrodes 122, which are perpendicular to the pairs of strip-shaped sustain electrodes 112 and 115, are arranged at a specific pitch. The partition walls 125 protrude vertically from the surface of the dielectric layer 123 and contacted with the opposing Mg0 layer 114 of the first component 111, resulting in strip-shaped discharge spaces 103 extending along the walls 125 between the first and second components 101 and 102. Each of the spaces 103 includes a corresponding one of the selection electrodes 122 located at the center of the corresponding space 103. The fluorescent strips 124 cover not only the exposed surface of the dielectric layer 123 but also the side faces of the partition walls 125, as shown in FIG. 1C.
The first and second components 101 and 102 are couples together so that the Mg0 layer 114 is opposed to the dielectric layer 123 at a specific distance. A discharge gas (not shown) is filled into the discharge spaces 103 to emit ultraviolet (UV) light for the purpose of exciting the fluorescent stripes 124. As shown in FIG. 1A, areas (approximately rectangular in shape) near the intersections of the pair of sustain electrodes 112 and 115 and the selection electrodes 122 form unit light-emitting areas, i.e., cells 105.
On operation of the prior-art PDP shown in FIGS. 1A to 1C, a specific voltage is applied across the pairs of sustain electrodes 112 and 115 to thereby generate and sustain electric discharge in the gas filled in the discharge spaces 103. Due to this electric discharge, UV light is emitted from the gas and irradiated to the fluorescent stripes 124. Thus, visible light is emitted from the fluorescent stripes 124. The visible light thus emitted can be seen through the first or second glass substrate 111 or 121.
One of each pair of sustain electrodes 112 and 115 is used as a common electrode and the other is used as a scan electrode. The selection electrodes 122 are used to select desired ones of the cells 105 for displaying a visible image on the PDP as necessary.
Typically, the visible light emitted from the fluorescent stripes 124 is seen through the first glass substrate 111. In this case, the pairs of sustain electrodes 112 and 115 are made of a transparent conductive material such as indium tin oxide (ITO), and the selection electrodes 122 are made of a conductive metal.
With the prior-art PDP shown in FIGS. 1A to 1C, the dielectric layer 113 of the first component 101 has an approximately uniform thickness over the whole layer 113. Therefore, if the thickness of the dielectric layer 113 is increased to improve the light-emitting efficiency, the discharge-sustaining voltage applied across the pairs of the sustain electrodes 112 and 115 needs to be raised, thereby arising a problem that the power consumption of the PDP is increased. On the other hand, if the thickness of the dielectric layer 113 is decreased to lower the discharge-sustaining voltage, a problem that the light-emitting efficiency degrades occurs.
Accordingly, an object of the present invention to provide a PDP that improves the light-emitting efficiency without raising the discharge-sustaining voltage, and a method of fabricating the PDP.
Another object of the present invention to provide a PDP that improves the light-emitting efficiency without increasing the power consumption, and a method of fabricating the PDP.
Still another object of the present invention to provide a PDP that realizes an improved display quality with low power consumption, and a method of fabricating the PDP.
The above objects together with others not specifically mentioned will become clear to those skilled in the art from the following description.
According to a first aspect of the present invention, a PDP is provided, which is comprised of
a first substrate;
a second substrate coupled with the first substrate to form a specific gap between inner surfaces of the first and second substrates;
pairs of a first sustain electrode and a second sustain electrode formed on or over the inner surface of the first substrate; the pairs of first and second sustain electrodes extending in a first direction and arranged at a specific pitch in a second direction perpendicular to the first direction; each of the pairs of first and second sustain electrodes being apart from each other at a specific gap;
a first dielectric layer formed on or over the inner surface of the first substrate to cover the pairs of first and second sustain electrodes;
selection electrodes formed on or over the inner surface of the second substrate to extend in the second direction; the selection electrodes being arranged in the first direction at a specific pitch;
a second dielectric layer formed on or over the inner surface of the second substrate to cover the selection electrodes;
partition walls formed in the gap between the inner surfaces of the first and second substrates to extend in the second direction; partition walls being arranged in the second direction at a specific pitch; the partition walls forming discharge spaces in the gap;
fluorescent layers formed respectively in the discharge spaces; and
a discharge gas introduced in the discharge spaces.
An overlapping part of the first dielectric layer with the first sustain electrode has a non-uniform thickness in a widthwise direction of the first sustain electrode. An overlapping part of the first dielectric layer with the second sustain electrode has a non-uniform thickness in a widthwise direction of the second sustain electrode.
With the PDP according to the first aspect of the present invention, the overlapping part of the first dielectric layer with each of the first sustain electrodes has a non-uniform thickness in the widthwise direction of the first sustain electrode, and the overlapping part of the first dielectric layer with each of the second sustain electrodes has a non-uniform thickness in the widthwise direction of the second sustain electrode. Therefore, for example, the thickness of the first dielectric layer can be decreased at a suitable part of the first sustain electrode and at a suitable part of the second sustain electrode. As a result, even if the discharge-sustaining voltage applied across each pair of the first and second sustain electrodes is lowered, the light-emitting efficiency of the PDP is improved according to the decreased thickness of the first dielectric layer. This leads to both low power consumption and good display quality.
According to a second aspect of the present invention, a method of fabricating the PDP according to the first aspect is provided, which is comprised of the following steps (a) to (c).
(a) Protrusions are formed on the inner surface of the first substrate to extend the first direction and to be arranged at a specific pitch in the second direction.
(b) The pairs of first and second sustain electrodes extending in the first direction are formed on the inner surface of first substrate to be overlapped with the protrusions.
(c) The first dielectric layer are formed on the inner surface of the first substrate to cover the pairs of first and second sustain electrodes in such a way that the overlapping part of the first dielectric layer with the first sustain electrode has a non-uniform thickness in a widthwise direction of the first sustain electrode and the overlapping part of the first dielectric layer with the second sustain electrode has a non-uniform thickness in a widthwise direction of the second sustain electrode.
With the method of fabricating a PDP according to the second aspect of the present invention, the PDP having the protrusions on the inner surface of the first substrate according to the first aspect can be obtained.
According to a third aspect of the present invention, another method of fabricating the PDP according to the first aspect is provided, which is comprised of the following steps (axe2x80x2) and (bxe2x80x2).
(axe2x80x2) The pairs of first and second sustain electrodes extending in the first direction are formed on the inner surface of the first substrate.
(bxe2x80x2) The first dielectric layer is formed on the inner surface of the first substrate to cover the pairs of first and second sustain electrodes. The first dielectric layer have depressions on its surface at an opposite side to the first substrate. Each of the depressions is located to be overlapped with the inner parts of the first and second sustain electrodes in each of the pairs.
With the method of fabricating a PDP according to the third aspect of the present invention, the PDP having the depressions on the opposite surface of the first dielectric layer to the first substrate according to the first aspect can be obtained.